A program of laboratory and clinical research directed at understanding the process of autologous marrow transplantation (AMI) and improving its results is proposed. Laboratory projects will be directed toward better understanding of the mechanisms of hematopoiesis in order to design methods of improving marrow function after AMI. Other laboratory projects will be directed at removing populations of malignant cells from marrow by lysis with monoclonal antibodies and complement or by positively selecting for hematopoietic progenitor cells. In vitro methods of detecting residual malignant cells after purging will also be evaluated. Clinical research will involve patients with acute lymphoblastic leukemia, acute nonlymphoblastic leukemia, malignant lymphoma, and multiple myeloma and will be directed towards defining the role of AMT in the treatment of these diseases as well as exploring ways to improve current results using new preparative regimens, better in vitro purging, and post-transplant biologic response modifiers. Core programs, essential in carrying out the proposed research projects, include Biostatistics and Information Services, Pathology, Outpatient Care and Long-term Follow-up, and Administration.